The use of agitator drive interruption mechanisms in vacuum cleaners is well known. Prior art vacuum cleaners have employed numerous configurations to selectively activate and deactivate the rotary agitator. Examples include belt shifting mechanisms, belt detensioning mechanisms, and the like.
It has been found that belt de-tensioning modules are particularly advantageous because the uncomplicated design reduces the risks of excessive belt wear and belt slipping. Such designs typically include a rotary agitator driven by a belt, and an idler arm carrying an idler pulley at one end. A spring biases the arm so that the pulley engages and thereby tensions the belt during normal, inclined operation. When the vacuum cleaner is placed in an upright position, a tab on the upper housing engages the idler arm to cause the idler pulley to pivot away from the belt. Tension is thereby released from the belt and the agitator is deactivated.
Though such arrangements have proven effective in the past, with the widespread availability and low costs associated with microprocessors, newer vacuum cleaners now include many more automated features. Consumers now expect to be able to control many or all of the vacuum cleaner functions from controls located on or proximate to the handle grip. Thus, there is a need in the art for vacuum cleaner configurations that electronically control agitator detensioning.